function ShoppingCart() {

	var _selectedPhotos = [] ;
	var _sizes = [] ;
	var _paperBorders = [] ;
	var _paperTypes = [] ;
	
	this.addPhotoToCart = addPhotoToCart;
	this.photosCount = photosCount;
	this.addSize = addSize;
	this.getSizes = getSizes;
	this.addPaperBorder = addPaperBorder;
	this.getPaperBorders = getPaperBorders;
	this.addPaperType = addPaperType;
	this.getPaperTypes = getPaperTypes;
	
	function addPhotoToCart(aPhoto){				
		_selectedPhotos.push(aPhoto);	
	}
	
	function addSize(aSize){				
		_sizes.push(aSize);	
	}
	
	function photosCount(){				
		return _selectedPhotos.length;	
	}
	
	function getSizes(){				
		return _sizes;	
	}
	
	function getPaperBorders(){				
		return _paperBorders;	
	}
	
	function addPaperBorder(aBorder){				
		_paperBorders.push(aBorder);	
	}
	
	function getPaperTypes(){				
		return _paperTypes;	
	}
	
	function addPaperType(aType){				
		_paperTypes.push(aType);	
	}
}